the fbi also wants to question tamerlan's wife, seen over the weekend, leaving the family apartment. a rhode island native, she converted to islam and changed her name from katherine to karima. because she lived in the same cambridge apartment where authorities believed the two brothers hatched their plot, she could provide clues about whether others were involved. her family issued a statement today saying, "we know now that we never really knew tamerlan tsarnaev." now a possible link to a murder, two years ago. local prosecutors said today they are investigatoring whether tamerlan was involved in the brutal murder of three young men, one of whom was his roommate. the three were found with their throats slashed, covered in marijuana and cash. also under investigation, the six-month trip he took to russia, at a time that rebel groups there carried out a number of violent attacks. as abc's kirit radia discovered in the dagestan region. >> last year alone, dagestan lost 115 police officers in nearly 300 terror attacks. just two years ago, this street was obliterated by a car bomb. >> r